NEW YORK - THE author of a new book about the wisdom of free products on the Web has acknowledged taking some liberties in his own work.

Chris Anderson, known for the influential business book 'The Long Tail', said he was mistaken for using passages - without attribution - that closely resembled material from Wikipedia and other sources included in his latest release, 'Free: The Future of a Radical Price'.

Anderson's book, coming out next month from Hyperion, includes information about the phrase 'there's no such thing as a free lunch,' about the meaning of a learning curve and about other subjects for which he depended on Wikipedia, the online encyclopedia of user-contributed articles. The similarities were first reported by the Virginia Quarterly Review.

The controversy already has been noted on Anderson's Wikipedia page.

Anderson explained on his blog that he had intended to include the URLs for the Wikipedia material, but that his publisher 'was uncomfortable with the changing nature of Wikipedia', and asked that Anderson note the date he viewed the page, a system the author found 'clumsy and archaic'.

In the 'rush' to finish the text, credit to Wikipedia was omitted. The passages in question 'were mostly on the margins of the book's focus, mostly on historical asides', Anderson said, 'but that's no excuse'.

Anderson, asked by The Associated Press why he had used Wikipedia, which has often been questioned for its reliability, Anderson said that 'on many subjects Wikipedia is one of the best, and best researched, sources, but you have to use other sources to confirm that. -- AP